The subject matter herein relates generally to isotope production systems and, more specifically, to systems and assemblies that are configured to directly or indirectly hold target material during isotope production.
Radioisotopes (also called radionuclides) have several applications in medical therapy, imaging, and research, as well as other applications that are not medically related. Systems that produce radioisotopes typically include a particle accelerator, such as a cyclotron, that accelerates a beam of charged particles (e.g., H− ions) and directs the beam into a target material to generate the isotopes. The cyclotron includes a particle source that provides the particles to a central region of an acceleration chamber. The cyclotron uses electrical and magnetic fields to accelerate and guide the particles along a predetermined orbit within the acceleration chamber. The magnetic fields are provided by electromagnets and a magnet yoke that surrounds the acceleration chamber. The electrical fields are generated by a pair of radio frequency (RF) electrodes (or dees) that are located within the acceleration chamber. The RF electrodes are electrically coupled to an RF power generator that energizes the RF electrodes to provide the electrical field. The electrical and magnetic fields cause the particles to take a spiral-like orbit that has an increasing radius. When the particles reach an outer portion of the orbit, the particles may form a particle beam that is directed toward the target material for isotope production.
Target material (also referred to as starting material) is typically housed within a target assembly that is positioned within the path of the particle beam. The target assembly may be attached to the cyclotron, positioned proximate to the cyclotron, or positioned away from the cyclotron. In some cases, a beam pipe may extend between the cyclotron and the target assembly. The particle beam is directed through the beam pipe and toward the target assembly. The target assembly includes a target body having a production chamber that holds the target material. The target material may be delivered and withdrawn from the production chamber by a fluidic circuit of tubes.
During the lifetime operation of an isotope production system, it is necessary to remove a target assembly for maintenance. For example, one or more parts of the target assembly may be replaced or cleaned to remove unwanted material that reduces production efficiency. The parts may be radioactive and, as such, it is desirable to limit the amount of time that a technician is exposed to the radioactive material. In order to secure the target assembly in the operative position, however, a number of steps must be performed to mechanically, fluidically, and electrically connect the target assembly to the isotope production system. For example, it may be necessary to secure the target body to another component, such as the cyclotron or the beam pipe, so that the path taken by the particle beam is vacuum sealed. In addition, the target assembly is often fluidically coupled to a number of tubes that deliver the target material and a cooling liquid. Each of these tubes may be separately coupled to a port of the system. The target assembly may also be electrically coupled to a control system so that the control system may, for example, monitor conditions of the target assembly. Each of these connections requires one or more steps to be performed, which increases the amount of time that a technician might be exposed to radioactive material. Moreover, if one or more of the above steps is performed incorrectly, the efficiency in producing isotopes may be reduced and/or the risk of damage to the isotope production system may be increased.